High Dynamic Range (HDR) displays can show images with higher color contrast levels and peak luminosities than the common Low Dynamic Range (LDR) displays. However, most existing video content is recorded and/or graded in LDR format. To show LDR content on HDR displays, it needs to be up-scaled using a so-called inverse tone mapping algorithm. Several techniques for inverse tone mapping have been proposed in the last years, going from simple approaches based on global and local operators to more advanced algorithms such as neural networks. Some of the drawbacks of existing techniques for inverse tone mapping are the need for human intervention, the high computation time for more advanced algorithms, limited low peak brightness, and the lack of the preservation of the artistic intentions. In this paper, we propose a fully-automatic inverse tone mapping operator based on mid-level mapping capable of real-time video processing. Our proposed algorithm allows expanding LDR images into HDR images with peak brightness over 1000 nits, preserving the artistic intentions inherent to the HDR domain. We assessed our results using the full-reference objective quality metrics HDR-VDP-2.2 and DRIM, and carrying out a subjective pair-wise comparison experiment. We compared our results with those obtained with the most recent methods found in the literature. Experimental results demonstrate that our proposed method outperforms the current state-of-the-art of simple inverse tone mapping methods and its performance is similar to other more complex and time-consuming advanced techniques.

A tone mapping operation (TMO) for HDR images with fixed-point arithmetic is proposed. A TMO generates a low dynamic range (LDR) image from a high dynamic range (HDR) image by compressing its dynamic range. Since HDR images are generally expressed in a floating-point data format, a TMO also deals with floating-point data even though resulting LDR images have integer data. As a result, conventional TMOs require many resources such as computational and memory cost. To reduce the resources, an integer TMO which treats a floating-point number as two 8-bit integer numbers was proposed. However, this method has the limitation of available input HDR image formats. The proposed method introduces an intermediate format to relieve the limitation of input formats, and expands the integer TMO for the intermediate format. The proposed integer TMO can be applied for multiple formats such as the RGBE and the OpenEXR. Moreover, the method can conduct all calculations in the TMO with fixed-point arithmetic. Using both integer data and fixed-point arithmetic, the method reduces not only the memory cost, but also the computational cost. The experimental and evaluation results show that the proposed method reduces the computational and memory cost, and gives almost same quality of LDR images, compared with the conventional method with floating-point arithmetic.

Background: Endometrial cancer vaginal recurrence in a patient deemed unsuitable for EBRT. Brachytherapy proposed although standard image-guidance insufficient.

Proposed Solution: PET-CT image-guidance.

Results: PET-CT acquired with brachytherapy applicator in situ. BTV delineated by the Nuclear Medicine physician. All subsequent volumes delineated by the Clinical Oncologist. 2 phase plan delivered with minimal toxicity.

Prostate cancer has been treated with low-dose rate (LDR) brachytherapy for early localised disease in the form of permanent seed implants, with all its inherent problems in terms of dosimetry and seed migration. High-dose rate (HDR) brachytherapy has mainly been utilised as a boost to external beam radiotherapy (EBRT) in patients with locally advanced disease. However, limited studies investigating HDR as a monotherapy for early local disease are yielding promising results in terms of biochemical control and reduced toxicity. With the ability to optimise the plan and conform the dose, dose escalation can be achieved whilst sparing normal tissue. Recent studies to assess the α/β ratio of prostate cancer have shown this to be low, making this tumour sensitive to large fractions or hypofractionation. The HDR delivery and large fraction sizes may be advantageous in tumours sensitive to radiation fraction size making HDR brachytherapy the treatment of choice over LDR brachytherapy and EBRT.

there is currently great interest in the treatment of prostate cancer due to its increasing profile in the older male population. in recent years brachytherapy has become a viable treatment option. low dose rate implants using permanently implanted radioactive seeds and high dose rate treatments using afterloading machines are two methods regularly used for the treatment of this disease. both techniques require close integration between imaging and the placement of the radioactive sources. future developments in imaging will lead to improved targeting of the radiation to diseased areas of the prostate and interactive treatment planning. this review paper describes the current status of the treatment of prostate cancer by brachytherapy, references current published results and examines radiation protection issues.